Explosion in downtown Nairobi, Kenya leaves many wounded (VIDEO)

Following the blast in central Nairobi, TV news images showed smoke pouring out of a heavily damaged building in the city center.

Firefighters extinguish a fire at the site of a blast in central Nairobi on Moi Avenue on May 28, 2012. A large blast that wounded dozens of people in the center of the Kenyan capital was labeled as a "terrorist" attack by Kenyan Prime Minister Raila Odinga. (TONY KARUMBA/AFP/Getty Images)

The cause of a large explosion in downtown Nairobi, Kenya earlier today was likely an improvised explosive device, according to the police, reported Agence France Presse.

The blast hit a complex full of small shops on Moi Avenue in Nairobi's business district. The Associated Press reported that local TV news images showed smoke pouring out of a heavily damaged building.

While Kenya's police chief blamed an electrical fault for the explosion, Prime Minister Raila Odinga said there was a terrorist link to the blast, AFP said.

Odinga said, "This is a heinous act. We are under threat but we will not be cowed," according to AFP.

The Associated Press said at least 33 people were injured. Among them was a woman who blamed the explosion on a "bearded man" who left a bag behind just before the blast.

Police chief Mathew Iteere said the police were reviewing the cause of the blast after hearing from a shopkeeper witness of a man who came into the shop and left a bag. He returned later, shortly before the blast, before rushing outside again. The police said they had a very good description of the suspect, according to AFP.

An eyewitness told The Nation newspaper that "there was a huge blast as debris flew in different directions," and the explosion shook nearby buildings.

There have been several grenade attacks in Kenya since it sent troops into southern Somalia last year following a wave of kidnappings of foreigners on Kenyan soil. The attacks have been blamed on the Al Qaeda-linked group Al Shabaab.

In May, one person died and five others were injured when gunmen threw explosives into a popular nightclub in the Kenyan port city of Mombasa.

No one claimed responsibility for the attack, though the pro-Al Shabaab site Al-Kataib reported on the explosion, said AFP.